Method and apparatus for crimping yarns



July 19, 1966 A. KUNZLE ETAL METHOD AND APPARATUS FOR CRIMPING YARNS 2 Sheets-Sheet 1 Filed June 25. 1964 INVENTORS 406L167- /(u/Yz/ 6 Luau/G Hayward y 1966 A. KUNZLE ETAL 3,

METHOD AND APPARATUS FOR CRIMPING YARNS Filed June 25, 1964 2 Sheets-Sheet 2 I/III/I/IIIIIIIIIIIIIIIII/IM INVENTORS Aususr KU/YZLE Y luow/e HO'PVATH United States Patent 3,261,116 METHOD AND APPARATUS FOR CRIMPING YARNS August Kunzle and Ludwig Horvath, Wattwil, St. Gall, Switzerland, assignors to Heberlein Patent Corporation, New York, N.Y., a corporation of New York Filed June 25, 1964, Ser. No. 377,845 Claims priority, application Switzerland, July 25, 1963, 9,263/ 63 Claims. (Cl. 57-34) This invention relates generally to the treatment of textile yarns, and, more particularly, to a method and apparatus for crimping yarns by false twisting without the use of a twsiting device.

Apparatus and processes for the crimping of textile yarns are known according to which two or more yarns are taken from spools, are twisted together along a selected length, are subjected to heat fixation while in the twisted condition, and are then separated into individual yarns by being pulled apart in different directions and at the same speed. When yarn is treated in this way, it has been observed that certain forces are often set up which overstress the yarn and cause it to break. Thus, for example, the respective yarns that are twisted together during heat fixation may suffer contraction to a different degree, or the fibers of one yarn may work into those of another, wherefore the point of separation of the yarns tends to deviate laterally as the yarns are pulled apart and breakage may occur.

Accordingly, we have conceived by our invention a method and apparatus by which we are able to overcome the foregoing difficulties and disadvantages. Thus, our invention encompasses a method and apparatus for permanently crimping yarns according to which at least two yarns are crimped together along a selected length or distance and are fixed while in twisted condition and then separated by being drawn apart in different directions at the same speed and each under a tension that is regulated by the application of a braking force to one or another of the yarns whenever uneven tensions develop in the yarns. By thus regulating the tensions in the respective yarns, we are able to compensate instantly for uneven tensions, thus eliminating breakage due to that factor.

As an important feature of our invention, we provide yarn braking means preferably positioned subsequent to the point of separation of the yarns in their direction of travel, and yarn guide means preferably positioned be, tween the point of separation and the braking means and engaging the individual separated yarns, the yarn guide means and braking means being shiftable relatively to one another in response to uneven tension in the yarns to render the braking means effective upon the yarn of greatest tension. We are thus able to eifect substantially instantaneous regulation of the yarn tension.

As a further feature of the present concept, we prefer to mount the braking means in fixed position and to mount the yarn guide means for oscillatory movement in a direction and to an extent dependent upon which of the yarns increases in tension relatively to the other and the degree of the increase. The guide means is so related to the braking means that upon shifting movement when the tension is unbalanced, it shifts the yarn of highest tension relatively to the brake means to enable the brake means to apply a braking force to that yarn, thus to equalize the tensions in the yarns.

The process and apparatus of the present invention are especially suited to the treatment, both of endless threads or bundles of filaments, as well as of staple fiber yarns of thermoplastic fiber material, especially those of polyamides such as polyhexamethyleneadipamide and condensates of epsilon-caprolactam or 11 aminoundeoaroic acid, polyesters such as polyethyleneglycol terephthalate,

3,261,116 Patented July 19, 1965 vinyl base material such as polyacrylnitril, or polyolefines such as polypropylene, as well as of mixed yarns of thermoplastic fibers and non-thermoplastic natural fibers.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better un derstood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen ior purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a schematic representation in plan of one form of apparatus according to the invention;

FIG. 2 is an elevational view of the apparatus of FIG. 1;

FIG. 3 is a detail view in elevation of one form of yarn braking means according to the invention;

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a plan view illustrating another form of the invention;

FIG. 6 is a view similar to FIG. 5, but illustrating another form of the invention;

FIG. 7 is an elevational view of the apparatus shown in FIG. 6;

FIG. 8 is a cross-sectional view taken along the line 8-8 of FIG. 7,

Referring now to the drawings, and particularly to FIGS. 1 to 4, there are shown two yarn ends 10 and 11 emanating from delivery spools 12 and 14 and passing a snubbing device including two metal bars 15 over which the yarns pass, and a third bar 16 positioned between the bars 15 but below same and under which the yarns are threaded, all the bars being parallel. The yarns then pass vertical guide bars 17 and a yarn feeding device comprising rollers 19 and 20, one of which is driven. The yarns are mutually twisted together along a preselected length or distance 21 extending from the feeding device to a separation point 22 and along which the yarns are subjected to fixation, as by heat, by known means not shown. The yarn separation point 22 is positioned between closely spaced parallel bars or rollers 24 wherefore the separation point is fixed against lateral movement.

A pair of cfireely rotating rollers 25, 26 are mounted on similar vertical shafts 27 fixed on a horizontal hearing plate 29 which may also serve to support the rollers 24.

The plate 29 also supports a vertical shaft 30 (FIG. 2) to which is pivoted a horizontal lever anrn 31 normally positioned parallel to the axis of the length 21 of twisted yarns, but which can swing about the shaft axis in the directions of the arrows A, A. At its free end, the arm 31 supports a carrier 32 which in turn carries a pair of fireely rotatable rollers 34, 35.

As shown in FIG. 4, the shaft 30 has 'latera l arms 36 that extend outwardly and then upwardly to support a braking means 37 comprising two parallel bars 39 extending horizontally and perpendicular to the axis of the twisted length 21 of yarns. 'llhis braking means 38 also includes a pair of stub bars 40 positioned between the bars'39 and in a plane parallel to the vertical planes thereof, but angu'lated to the horizontal plane thereof in a direction to converge upwardly, for example. Actually, these stub bars 40 approach one another but need not come together. In any case, when viewed among the line 44 of FIG. 2, as in FIG. 4, the bars 40 will be seen to form opposed crotch/es with the bars 39, for a purpose presently to be made clear.

After passing the bars or rollers 24, the yarns 10, 11 diverge in the direction of travel, each passing around one of the rollers 25, 26 respectively, these being spaced further apart than the bars 24. The yarns then converge towards the rollers 34, 35 along the inner sides of which they pass respectively; thence passing on to the braking means 37.

As best shown in FIGS. 3 and 4, the yarns 10, 11 advance over the parallel bars 39 and beneath the stub bars 40, after which they move on to a delivery mechanism 41 comprising rollers 42, 44 one of which, preferabl the larger one, is driven for delivery to a suitable winding or take-up device (not shown).

During operation if, for example, the withdrawal tension of the separated yarn exceeds its normal value, then the swinging arm 31 will move in the direction of the arrow A, thus allowing the yarn 10' to shift laterally towards its respective crotch formed by the bars 39 and one of the stub bars 40, while the yarn 11 moves away from its crotch. 'Ilhe yarn 10 is thus seized and braked by the bars 39 and 40. As the tension in yarn 10 is reduced to its normal value between the separation point 22 and the brake means 37, the swinging arm 31, under the tension :of the yarn 11, moves back to its central position. A similar sequence takes place when the tension in yarn 11 increases, the arm 31 in this case swinging in the direction of the arrow A.

In the modification illustrated in FIG. 5, a T-shaped lever arm 45 is pivoted on the same shaft that mounts the bars or rollers 24, and extends along in the direction of yarn travel. At its free end, the lever arm 45 has a cross-piece 46, each end of which mounts a roller 47 and 49, respectively. The rollers -and 26 are positioned relatively to the separation point as in the embodiment illustrated in FIGS. 1 and 2.

In this case, the brake means are illustrated as comprising a pair of porcelain cylindrical segments 50, 51 positioned respectively adjacent the yarns 10, 11 moving from the rollers 47, 49 towards the delivery rollers (only one 42 of which is shown). If the yarn tension increases in yarn 10, for example, the unbalanced tension will swing the lever arm 45 in the direction of the arrow A by acting on the IOil lfil' 47 so that the yarn 10 contacts and is snubbed or braked by the surface of segment 50. As the braking action reduces the tension in the yarn 10, the tension in the yarn 11 acting on the roller 49 swings the arm 45 back towards its normal center position. A similar sequence takes place if the tension in yarn 11 increases, the arm 45, in this case swinging in the direction of the arrow A, and surface of segment 51 acting to snub or brake the yarn 11.

In the modification of FIGS. 6 to 8, the structure is identical with that described in connection with the embodiment of FIGS. 1 to 4 except that the braking means 37 is not used. Rather, in this case the rollers 34 and are respectively furnished with circular discs or flanges 55, 56 for rotation therewith; and a pair of permanent or electromagnets 57, 59 are positioned adjacent the discs 55, 56 respectively, but a sufficient distance from them so that when the anrn 31 is in its normal position, the lines of magnetic flux of the magnets are not affected by the discs. However, if the yarn tensions become unbalanced after separation, the arm 31 will shift in the direction of the arrows A or A depending upon which yarn is under the greater tension. Thus, if yarn 10 is under high tension, the arm 31 shifts in the direction of the arrow A bringing the disc 55 between the poles of the magnet 57. The lines of magnetic flux generated by the magnet are cut by the disc causing the production of eddy currents in the disc with a resultant braking action on the disc, the roller 34 and consequently on the yarn 10. As the tension is relaxed, the arm 31 is returned to normal position by the tension in the yarn 11.

The arm 31 swings in the direction of the arrow A when the yarn tension becomes unbalanced due to an increase in the tension in ya rn 11. Such action brings the disc 56 between the poles of the magnet 59 producing the eddy current effect in disc 56 and a braking action on yarn 11.

From the foregoing description, it will be seen that we have conceived a method and apparatus useful in the crimping of textile yarns by which we are able reliably and substantially instantly to correct and regulate conditions of unbalanced tension in yarns after separation thereof from a condition of mutual twisting while the yarns are being linearly advanced, by the application of a braking force to one or the other of the yarns when the tension thereof is increased.

We believe that our novel method and apparatus for the crimping of textile yarns will now be understood, and that our invention will be fully aipppreciated by those persons skilled in the art.

' We new claim:

1. In apparatus for permanently crimping textile yarns in which at least two yarns are twisted together along a selected distance and are fixed while in twisted condition and then separated by being drawn apart in different directions at the same speed; yarn braking means, and yarn guide means engaging the individual separated yarns, one of said means being shiftable in relation to the other in response to uneven tension in the yarns to render the brake means effective upon the yarn of greatest tension.

2. In apparatus for permanently crimping textile yarns in which at least two yarns are twisted together along a selected distance and are fixed while in twisted condition and then separated by being drawn apart in different directions at the same speed; yarn braking means, and yarn guide means engaging the individual separated yarns and shifting in response to uneven tension in the yarns to render said brake means effective upon the yarn of greatest tension.

3. In apparatus for permanently crimping textile yarns in which at least two yarns are twisted together along a selected distance and are fixed while in twisted condition and then separated by being drawn apart in different directions at the same speed; yarn braking means positioned subsequent to the point of separation of the yarns in their direction of travel, and guide means including a lever mounted at one end for swinging movement in a plane parallel to the plane of the separated yarns and carrying yarn guide elements at its free end and on opposite sides of its longitudinal axis, each said element engaging one of applied to it.

4. Apparatus according to claim 3, wherein the axis of the twisted length of yarns and the pivot axis of said lever are disposed at the yarn guide elements are symmetrically arranged on each side of said lever, and the yarns engage fixed guides positioned outwardly and in ad Vance of said elements while advancing towards said elements.

5. In apparatus for permanently crimping textile yarns in which at least two yarns are twisted together along a selected distance and are fixed while in twisted condition and then separated by being drawn apart in different directions at the same speed; yarn braking means including snubbing surfaces operable to apply a braking force to a yarn brought into engagement with such surfaces, and yarn guide means engaging the individual separated yarns and shifting in response to uneven tension in the yarns to render said brake means effective upon the yarn of greatest tension.

6. Apparatus according to claim 5, wherein the snub'bing surfaces are formed by bars positioned angularly relatively to one another to snub the yarns as they are moved towards the crotch thereof.

7 Apparatus according to claim 5, wherein the snubbing surfaces are cylindrical segments positioned adjacent the yarns as they advance beyond the point of separation.

8. In apparatus for permanently crimping textile yarns in which at least two yarns are twisted together along a selected distance and are fixed while in twisted condition and then separated by being drawn apart in different directions at the same speed; yarn guide means including a lever mounted at one end for swinging movement and carrying yarn guide elements at its free end and on opposite sides of its longitudinal axis, each element engaging one of the individual separated yarns, said lever swinging from its normal position in response to an uneven ten sion in said yarns, and yarn brakes including magnets positioned adjacent said elements and discs rotatable and swingable with said elements to enter the field of the adjacent magnet upon swinging movement of said lever to generate braking eddy currents in the disc associated with said element engaging the yarn of high tension.

9. A method of permanently crimping textile yarns wherein at least two yarns are temporarily twisted together along a selected distance, are subjected to fixation while twisted, and are drawn apart in different directions under substantia ly equal tension, characterized by sensing unbalanced tensions in the yarns, shifting the yarns relatively to tension compensating means in response to such unbalance, applying unbalanced tensions to the shifted yarns in inverse proportion to the initial unbalance to compensate for the initial unbalance, and returning the yarns to their normal position when the tensions are balanced.

It A method of permanently crimping textile'yarns wherein at least two yarns are temporarily twisted together along a selected distance, are subjected to fixation while twisted, and are drawn apart in different directions under substantially equal tension, characterized by sensing unbalanced tensions in the yarns, shifting the yarns relatively to braking means in response to such unbalance to "bring the yarn of greater tension into position for the application thereon of a braking force and applying a braking force to such yarn of greater tension to eliminate the unbalance.

References Cited by the Examiner UNITED STATES PATENTS 2,881,504 4/1959 Billion 28-72 2,987,869 6/1961 Klein 57-34 3,091,908 6/1963 Carrut hers 57-34 3,192,697 7/1965 Carruthers 5734 FOREIGN PATENTS 1,197,715 6/1959 France.

1,251,346 12/1960 France.

STANLEY N. GILREATH, Primary Examiner.

D. E. WATKINS, Assistant Examiner. 

1. IN APPARATUS FOR PERMANENTLY CRIMPING TEXTILE YARNS IN WHICH AT LEAST TWO YARNS ARE TWISTED TOGETHER ALONG A SELECTED DISTANCE AND ARE FIXED WHILE IN TWISTED CONDITION AND THEN SEPARATED BY BEING DRAWN APART IN DIFFERENT DIRECTIONS AT THE SAME SPEED; YARN BRAKING MEANS, AND YARN GUIDE MEANS ENGAGING THE INDIVIDUAL SEPARATED YARNS, ONE OF SAID MEANS BEING SHIFTABLE IN RELATION TO THE OTHER IN RESPONSE TO UNEVEN TENSION IN THE YARNS TO RENDER THE BRAKE MEANS EFFECTIVE UPON THE YARN OF GREATEST TENSION. 